In
computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, ...
system generation or sysgen is the process of creating a particular unique instance of an
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also i ...
by combining user-specified options and parameters with manufacturer-supplied general-purpose program code to produce an operating system tailored for a particular hardware and software environment.
Some other programs have similar processes, although not usually called "sysgen." For example,
IBM's
Customer Information Control System
IBM CICS (Customer Information Control System) is a family of mixed-language application servers that provide online transaction management and connectivity for applications on IBM mainframe systems under z/OS and z/VSE.
CICS family products ...
(CICS) was installed through a process called ''CICSGEN''.
Rationale
A large general-purpose program such as an operating system has to provide support for all variations of
Central processing unit
A central processing unit (CPU), also called a central processor, main processor or just Processor (computing), processor, is the electronic circuitry that executes Instruction (computing), instructions comprising a computer program. The CPU per ...
(CPU) that it might be run on, for all supported
main memory sizes, and for all possible configurations of
input/output
In computing, input/output (I/O, or informally io or IO) is the communication between an information processing system, such as a computer, and the outside world, possibly a human or another information processing system. Inputs are the signals ...
(I/O) equipment. No one installation requires all this support, so system generation provides a process for selecting the options and features actually required on any one system.
Sysgen produces a system that is most efficient in terms of CPU time, main memory requirements, I/O activity, and/or disk space. Often these parameters can be traded off, for example to generate a system that requires less memory at the expense of increased disk I/O operations.
See also
*
System Generation (OS)
System Generation (SysGen) is a two-stage process for installing or updating OS/360, OS/VS1,
OS/VS2 (SVS), OS/VS2 (MVS) and chargeable systems derived from them. There are similar processes for, e.g., DOS/360, which this article does not cover. ...
References
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System software